Preferred molecular test following biochemical testing suggestive of arginine:glycine amidinotransferase (AGAT) deficiency.
Polymerase Chain Reaction/Sequencing
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Background Information for Arginine:Glycine Amidinotransferase (GATM) Deficiency Sequencing:
Characteristics: Intellectual disability and seizure disorder of variable severity. May also include speech / language delays, movement disorder, and behavioral disorders such as autism, hyperactivity, and self-injury.
Incidence: Unknown. Less than 15 cases have been described.
Inheritance: Autosomal recessive.
Cause: Pathogenic GATM gene mutations.
Clinical Sensitivity: Based on limited data, may be as high as 99 percent.
Methodology: Bidirectional sequencing of the entire coding region and intron/exon boundaries of the GATM gene.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Mutations in genes other than GATM are not evaluated.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|2011145||AGAT (GATM) Sequencing Specimen||31208-2|
|2011146||AGAT (GATM) Sequencing Interpretation||35474-6|
- AGAT Deficiency, GAMT, Guanidinoacetate Methyltransferase, GAA, SLC6A8, creatine deficiency, creatin